Non-conjugated spacer embedded polymer donors enable superior blend miscibility for high-performance and mechanically-robust polymer solar cells
발표자
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초록
내용
Here, we develop a series of novel polymer donors (PDs), with which highly efficient PSCs with remarkable mechanical reliability are demonstrated. By interposing controlled amount of 1,10-di(thiophen-2-yl)decane flexible spacer (FS) into a PM6 backbone, we are able to significantly enhance the intermixing of the new PDs with small molecule acceptor (Y7). As a result, PSCs based on the PD containing 5 mol% FS unit and Y7 exhibit a high power conversion efficiency (PCE) of 17% with a crack onset strain (COS) of 12% and a cohesive fracture energy (Gc) of 2.1 J m–2, significantly outperforming the reference PM6-based devices (PCE = 15%, COS = 2% and Gc= 1.0 J m–2). Both the photovoltaic performance and mechanical robustness of these PSCs are among the best values reported to date. The rational design of PDs demonstrated here presents a highly promising strategy to address the mechanical properties of SMA-based solar cells and their viable application in flexible/stretchable electronics.